7.3 Application problems
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48
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Problem
Cause
Remedy
Stirrer motor jammed.
Check whether it is possible to manually rotate
the stirrer. If it does not rotate freely, contact
your local Metrohm Service.
scTRACE Gold - the
electrode disinte-
grates very fast.
Activation and/or cleaning
of the electrode is carried
out too often.
Verify that it is necessary to clean the electrode
so often. In some cases a measurement in
standard solution instead of sample is suffi-
cient to clean the electrode.
The working electrode has
oxidized during the mea-
surement.
Components of the sample matrix, e.g. chlor-
ide, can facilitate the oxidation of the elec-
trode
(see "Influence of chloride", page 61)
Survey the composition of your sample and
adapt the voltammetric parameters if neces-
sary.
Organic solvents are used.
The printed parts of the scTRACE Gold elec-
trode are not resistant against organic sol-
vents. Therefore, no organic solvents, not even
ethanol, should be used for cleaning or as part
of the measuring solution.
7.3
Application problems
Problem
Cause
Remedy
Calibration curve -
the calibration curve
is not displayed or
calculated.
The peaks are not evalu-
ated.
See
Peak evaluation - peaks are not evalu-
ated.
Calibration curve is not
monotonic.
The calibration curve has to be either monot-
onically decreasing or increasing. The reason
that the calibration curve is not monotonic can
be an outlier of an individual point or a ran-
dom distribution of calibration points.
Individual outlier
■
Adapt the evaluation parameters to get
also the outlier peak evaluated
"Adapting the baseline parameters for all
curves", page 30)
■
Set the base points for the outlier manually
to evaluate the peak correctly
Summary of Contents for 2.946.0010
Page 1: ...946 Portable VA Analyzer 2 946 00x0 Manual 8 946 8003EN ...
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Page 12: ...1 4 Symbols and conventions 4 Note This symbol marks additional information and tips ...
Page 79: ... 8 Technical specifications 71 8 8 Connection Connection USB version 1 1 or higher ...